The objective of this work is to evaluate how effective vaccines against the AIDS virus can be prepared using a small synthetic peptide as an antigen. The recent observation that HIV mutates very rapidly in vivo suggests a potential disadvantage of a specific HIV strain derived recombinant envelop protein as a vaccine candidate. The large envelope protein GP120 lacks the ability to present to the host only the desired epitope(s). A "small synthetic peptide" as a vaccine may be an alternative approach to overcome this lack of instruction, since one may be able to direct the host to the desired epitope more readily. However, if this approach is to be successful, one needs to present the peptide in its native conformation. We have been evaluating the approach of grafting a test peptide onto a larger known tertiary structure host molecule or a conformationally constrained peptide tertiary structural template (PTST) molecule for stabilizing the test peptide's solution conformations to near its native conformation. Our initial evaluation of this PTST concept for constraining and stabilizing the test peptide's conformation using various viral and non-viral protein-protein interaction systems such as fibronectin CS1 domain, epidermal growth factor receptor binding domain and the central and newly identified Respiratory Syncytial Virus neutralizing epitopes are being examined.